1. Field of the Invention
The present invention relates to an image recording apparatus which operates in synchronism with a vertical scan synchronization signal (hereinafter a VSYNC signal) from an image signal generator to output a vertical scan signal synchronization signal request signal (hereinafter a VSREQ signal) indicating that the VSYNC signal is acceptable.
2. Related Background Art
In a laser beam printer, a start of print signal (hereinafter a PRNT signal) is outputted to a printer engine (hereinafter an image recording apparatus) from an apparatus (hereinafter a controller) for outputting an image signal in synchronism with a so-called BD signal, and the image recording apparatus starts a print preparation operation in response thereto, and when it is ready to receive a VSYNC signal, it renders the VSREQ signal true to the controller. (A status in which the VSREQ signal is true, that is, when the VSYNC signal is acceptable is called a print enable state.)
When the controller then renders the VSYNC signal true, a print operation is started.
In some image recording apparatuses, the VSYNC signal from the controller is permanently monitored after the VSREQ signal is rendered true, and in other image recording apparatuses, an error is detected if the VSYNC signal is not received with in a predetermined period after the VSREQ signal bas been rendered true.
However, in the prior art, different controllers are required depending on whether the image recording apparatus to be connected is the former type or the latter type. It is not possible to connect the image recording apparatus of the latter type to the controller which is to be connected to the image recording apparatus of the former type.
Accordingly, such recording apparatus lacks the general purpose usability and if it is misconnected, it will lead to malfunction or trouble.